The Cell Imaging and Histology Shared Resource provides the equipment and expertise for three types of services: 1) High resolution microscopic techniques to obtain information about the morphology of cells, and sophisticated imaging techniques to analyze the distribution of molecules and their interactions within their cellular environment; 2) Histological and immunohistological techniques to study the morphology of normal and pathological specimens and the distribution of molecules in tissues; and 3) electron and immunoelectron microscopy to analyze the ultrastructure of of cells and the association of molecules with subcellular organelles. The Resource operates four light micsroscopes for confocal and standard imaging and an electron microscope for ultrastructural analysis. Equipment and services are provided for tissue embedding, sectioning, laser capture dissection, staining, and microscopic analysis of specimens. The goals for the next five years include expansion of existing services and introduction of new services. An increased effort will be placed on assisting users with the design and set-up of experiments, including sample collection and processing. New advanced optical imaging strategies for visualizing molecular events in living cells will be implemented, such as: 1) Optical imaging based on the principle of fluorescence resonance energy transfer (FRET) and fluorescent lifetime imaging (FLIM); 2) Total internal reflection fluorescence microscopy (TIRF) to register real-time interactions and trafficking of fluorescent molecules, and to study the dynamics of protein-protein interactions and enzymatic reactions in live cells; and 3) Fluorescence recovery after photobleaching (FRAP) to examine the lateral diffusion and mobility of fluorophore-labeled molecules into an area that has been photobleached. Overall the Cell Imaging and Histology Shared Resource provides essential microscopic and histological services and will accommodate the increased use and requirement for new services in response to new research initiatives at the Cancer Center.